So basically, what you are saying that after eliminating the obvious: spark plugs and coils, it could be a wide variety of things that can cause a misfire: anything from carbon build up, bad fuel injector, fuel pump , etc etc.

...not the moon phase?

What do you suggest for my situation:

* 25K miles on car
* Brand new spark plugs
* Swapping coils does not move the misfires to a different cylinder
* Injectors and HPFP replaced less than 5K miles during recall campaign

I would try fuel injection cleaner. I know many say it does nothing to Di engines, but i can swear it eliminated some of hesitation on hard acceleration. Cheap enough to try.

I bought my 08' with 54k miles on it less then two months ago. Installed the JB4 and I instantly started getting misfire codes for cylinders 3, 4, and multiple cylinders that same day. I have since changed the plugs and moved the coils around with no luck. I'm still getting misfires on 3 and occasionally 4 and 1.
The problem happens almost ALL the time at part throttle (75% max) from 2k - 5k rpm and the car stutters/shakes and starts running rough until I re-start the car. It's gotten to the point that it even happens on map 0 now But the strange part is, that if I just hammer down the gas pedal, most of the time it will run like a raped ape to redline with no misfires! But anything in-between 2k and 5k rpm accelerating moderately (which is most of my daily spirited driving) it misfires bad

Anyway, I called the BMW dealer I bought the car from (the car was originally bought, serviced, and traded back in from this dealer) and set up an appointment to have them look at it. I gave them the VIN and supposedly the recalls were done already and the HPFP was replaced sometime in 2010 and the injectors in Jan 2011... And of course the OEM warranty was up when I bought the car, but I'm still under the dealers 60 day used car warranty. So I'm hoping they find some bad injectors or coils and fix it for me!

This just sucks... so now I'm pulling out the JB4 and putting the car back to stock tonight, and leaving the SES light on with the 3 misfire codes still showing.

Sounds like LPFP starting to go. Sometimes it wont even throw a code and will just fail completely one day then throw a code. Once they change that and fuel pressure regulator everything will be peachy and you will discover that's what was causing your misfires.

I bought my 08' with 54k miles on it less then two months ago. Installed the JB4 and I instantly started getting misfire codes for cylinders 3, 4, and multiple cylinders that same day. I have since changed the plugs and moved the coils around with no luck. I'm still getting misfires on 3 and occasionally 4 and 1.
The problem happens almost ALL the time at part throttle (75% max) from 2k - 5k rpm and the car stutters/shakes and starts running rough until I re-start the car. It's gotten to the point that it even happens on map 0 now But the strange part is, that if I just hammer down the gas pedal, most of the time it will run like a raped ape to redline with no misfires! But anything in-between 2k and 5k rpm accelerating moderately (which is most of my daily spirited driving) it misfires bad

Anyway, I called the BMW dealer I bought the car from (the car was originally bought, serviced, and traded back in from this dealer) and set up an appointment to have them look at it. I gave them the VIN and supposedly the recalls were done already and the HPFP was replaced sometime in 2010 and the injectors in Jan 2011... And of course the OEM warranty was up when I bought the car, but I'm still under the dealers 60 day used car warranty. So I'm hoping they find some bad injectors or coils and fix it for me!

This just sucks... so now I'm pulling out the JB4 and putting the car back to stock tonight, and leaving the SES light on with the 3 misfire codes still showing.

Nope, I've cleared the codes about a dozen times now, and I've never gotten anything but misfire codes for the specific cylinders and the multiple cylinder misfire code, and thats it... no other codes.
Before the new plugs, it was only cylinders 3 and 4 every time (and I reset the codes 3 or 4 times)
Then I replaced all the plugs and I switched the #3 and #4 coils to the #1 and #2 spots.... and now I still get a misfire code from #3 every time, and occasionally #1 and #2, show up also... So, I'm wondering if I have a couple coils going bad, and one injector in the #3 spot.

Quote:

Originally Posted by vase330

Sounds like LPFP starting to go. Sometimes it wont even throw a code and will just fail completely one day then throw a code. Once they change that and fuel pressure regulator everything will be peachy and you will discover that's what was causing your misfires.

That would be nice if it were that easy, and simply replacing the pump, but that wouldnt be my luck!
I guess we'll find out what the dealer finds when I take it in, either tomorrow or Monday.

I bought my 08' with 54k miles on it less then two months ago. Installed the JB4 and I instantly started getting misfire codes for cylinders 3, 4, and multiple cylinders that same day. I have since changed the plugs and moved the coils around with no luck. I'm still getting misfires on 3 and occasionally 4 and 1.
The problem happens almost ALL the time at part throttle (75% max) from 2k - 5k rpm and the car stutters/shakes and starts running rough until I re-start the car. It's gotten to the point that it even happens on map 0 now But the strange part is, that if I just hammer down the gas pedal, most of the time it will run like a raped ape to redline with no misfires! But anything in-between 2k and 5k rpm accelerating moderately (which is most of my daily spirited driving) it misfires bad

Anyway, I called the BMW dealer I bought the car from (the car was originally bought, serviced, and traded back in from this dealer) and set up an appointment to have them look at it. I gave them the VIN and supposedly the recalls were done already and the HPFP was replaced sometime in 2010 and the injectors in Jan 2011... And of course the OEM warranty was up when I bought the car, but I'm still under the dealers 60 day used car warranty. So I'm hoping they find some bad injectors or coils and fix it for me!

This just sucks... so now I'm pulling out the JB4 and putting the car back to stock tonight, and leaving the SES light on with the 3 misfire codes still showing.

Quote:

Originally Posted by Eracer76

Nope, I've cleared the codes about a dozen times now, and I've never gotten anything but misfire codes for the specific cylinders and the multiple cylinder misfire code, and thats it... no other codes.
Before the new plugs, it was only cylinders 3 and 4 every time (and I reset the codes 3 or 4 times)
Then I replaced all the plugs and I switched the #3 and #4 coils to the #1 and #2 spots.... and now I still get a misfire code from #3 every time, and occasionally #1 and #2, show up also... So, I'm wondering if I have a couple coils going bad, and one injector in the #3 spot.

I was actually thinking that exact thing. Perhaps you have some carbon build up too though.

Nope, I've cleared the codes about a dozen times now, and I've never gotten anything but misfire codes for the specific cylinders and the multiple cylinder misfire code, and thats it... no other codes.
Before the new plugs, it was only cylinders 3 and 4 every time (and I reset the codes 3 or 4 times)
Then I replaced all the plugs and I switched the #3 and #4 coils to the #1 and #2 spots.... and now I still get a misfire code from #3 every time, and occasionally #1 and #2, show up also... So, I'm wondering if I have a couple coils going bad, and one injector in the #3 spot.

Does JB4 had a auto code clear function?

I had limp mode a couple of times and I was only getting limp mode code, then realise that the procede was clearing the other codes.

This forum is making me a bit nervous. I bought my 07' 335i with 15k on it two years ago, now at 27k I haven't really had any issues other than a footwell module & the HPFP recall. I had planned on keeping this car as it's my favorite of all time but all the issues posted here i.e. coils, plugs, injectors, carbon build-up, etc. have me second guessing that decision. It almost seems as if it's a matter of when not if something will fail prematurely.

This forum is making me a bit nervous. I bought my 07' 335i with 15k on it two years ago, now at 27k I haven't really had any issues other than a footwell module & the HPFP recall. I had planned on keeping this car as it's my favorite of all time but all the issues posted here i.e. coils, plugs, injectors, carbon build-up, etc. have me second guessing that decision. It almost seems as if it's a matter of when not if something will fail prematurely.

It mainly comes with the territory of running an aggressive map. Misfires may not even show up running stock or a basic stage 1 map on any tune. Fortunately, it is fairly straightforward to diagnose and replace the usual suspects - plugs and coils. It does not cost that much either; I would not let this deter you from keeping and enjoying your car

This forum is making me a bit nervous. I bought my 07' 335i with 15k on it two years ago, now at 27k I haven't really had any issues other than a footwell module & the HPFP recall. I had planned on keeping this car as it's my favorite of all time but all the issues posted here i.e. coils, plugs, injectors, carbon build-up, etc. have me second guessing that decision. It almost seems as if it's a matter of when not if something will fail prematurely.

Plugs and coils eventually fail on any car.

Carbon build up is inevitable on DI motors with any car.

Injectors are also common failure on DI motors.

All of this just comes with the territory. I always tell people to stay in warranty. I know I'm out of this car as soon as its done.

Car is great but too many quirks.

If you view any car forum all you see is the "Bad news". Since the information is here its not really a big deal. A few dollars here and there to make great power for a little money isnt a bad deal.